The present invention relates to a blade head especially for cutting and planing blades for wood or plastic machining devices. The blade head has a blade holder with a plurality of receiving grooves for receiving a cutting and planing blade, the receiving grooves distributed over the circumference of the blade holder; a plurality of pressurizing elements positioned in each of the receiving grooves for holding the cutting and planing blade within the receiving groove; and an adjusting member positioned in each of the receiving grooves for forcing the pressurizing elements against one another such that the pressurizing elements exert a clamping pressure on the cutting and planing blade.
For clamping blades within a known blade heads, commonly a hydroclamping sleeve is used with which via pistons the pressure medium is applied. The pressurizing elements for clamping the blades are outwardly forced whereby the blade is thus secured within the receiving grooves. A disadvantage of these known blade heads is that the clamping pistons within the blade holder are radially positioned between the receiving grooves and an opening for the spindle of the blade head. This arrangement results in a weakened structure of the blade holder within the radial area. Furthermore, the blades can become loose when the hydroclamping sleeve or one of the clamping pistons has a leak.
From European publication 0 182 037 a blade head is known in which the blades are clamped by steel balls resting at one another within the receiving groove. They are forced against one another by an adjusting element in the form of a set screw whereby they are alternately forced radially outwardly and radially inwardly and rest under prestress at the bottom of the receiving groove as well as at the abutment surfaces of the blades. With the steel balls only a point contact at the corresponding counter clamping surfaces is achieved so that these counter clamping surfaces as well as the steel balls are subject to a considerably high load and therefore also to great wear.
It is therefore an object of the present invention to provide a blade head of the aforementioned kind with which the blades can be clamped in a simple and reliable manner without substantially weakening the blade holder whereby a high load on the parts partaking in the clamping process should be prevented.